Gas control unit



Nov. 3, 1964 5. J. BUDLANE 3,155,144

GAS CONTROL UNIT Filed July 20, 1961 s Sheets-Sheet 1 9 FigJ.

by vifmuw Altar/763g.

Nov. 3, 1964 5. J. BUDL ANE GAS CONTROL UNIT Filed July 20, 1961 3 Sheets-Sheet 2 [HI/(9)760)": Stan/syJBud/ane,

AUZ'O Nov. 3, 1964 5. J. BUDLANE GAS CONTROL UNIT 5 Sheets-Sheet 3 Filed July 20, 1961 fm/azrtan' 527621439 Jfiud/a United States Patent 3,155,144 GAS CGNTRSL UNIT Stanley J. Budiane, Morrison, lit, assignor to General Electric Company, a corporationof. New York Filed July 2%, 1961, er. No. 125,453 Claims. (Cl. 158-123) My invention relates to safety devices for controlling the operaion of a burner and more particularly to thermal-ly responsive structures which actuate one or more switches in respnose to the presence or absence of flame propagated by a fluid burner or the like.

An important object of this invention is to provide a novel and improved thermally responsive mechanism which is dependable in operation and is very quickly responsive to the presence or absence of a flame.

Another object of my invention is to provide a compact safety control unit which is especially adaptable for controlling the ignition of a gas burner, and includes a thermally responsive means which is rapidly and efficiently operative in an improved manner to detect the presence or absence of a flame and signal this detection to a controlling switch.

An additional object of this invention is to provide an improved safety control unit which is simple and compact in structure, readily manufactur-able, and low in cost.

In carrying out my invention, in one form thereof, I apply it to a safety control unit associated with a gas burner. The burner includes a series of ports which are formed in an elongated side thereof for directing flame outwardly from that side of the burner. A flame detector of elongated tubular configuration is supported at one of its ends near the burner. This detector is of the type which responds to the impingement of flame generally directed to one side of the detector by bending or warping to operate a switch for signalling the presence of burner flame. In this arrangement, a special bafile means is disposed near the burner and the flame detector. This bafiie means is arranged to provide a first limited flow path for movement of air to the flame impinging on the one side of the flame detector, and a second limited flow path for movement of air around the relatively cooler other side of the flame detector. The first and second limited flow paths which are provided by this special baffle means serve to restrict the flame to the first-mentioned side of the flame detector, while also tending to raise the temperature of the flame impinging on the heated side of the flame detector to an optimum level. Such an arrangement considerably enhances the efliciency of operation of the flame detector.

Further aspects of vmy invention will become apparent hereinafter and the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which I regard as my invention. The invention, however, as to organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the foil wing description when taken in coniunction with the accompanying drawings, in which:

PEG. 1 is a front elevation view of a burner mounted safety control unit embodying my invention in one form thereof;

FIG. 2 is a right end view of the safety control unit of FIG. 1, showing the front of the electric igniter and a sectional view of the gas burner upon which the safety control unit is mounted;

FIG. 3 is a bottom view of the safety control unit of FIG. 1;

FIG. 4 is a left end view of the safety control unit of FIG. 1;

ice

FIG. 5 is a sectional view taken along the line 5-5 of FIG. 1, and illustrating by enlarged flow arrows, the paths of secondary air and the effect which this air movement has upon flames effected by the ignition of gas emanating from the burner;

FIG. 6 is a fragmentary plan view of the burner safety control unit illustrating the mode of operation of the tubular flame detector;

FIG. 7 is a plan view of the control box of the safety control unit with the cover thereof removed; and

FIG. 8 is an elevational view of the control box of the safety control unit with the cover thereof removed.

Referring in detail to the drawings, and in particular to FIGS. 1-4, there is shown a safety control unit It for a gas burner 2 with which my invention has beenadvantageously employed. Such a control unit is sometimes also referred .to by those skilled in the art as a master control unit. The safety control unit 1 has an elongated over-all appearance, and essentially includes flame detector 3 which senses and responds to the presence of a flame, baffle 5 which enhances the efiiciency of operation of the flame detector 3 in accordance with my invention, control box '7 which supports and contains the actuating end of the flame detector as well as various other controlling elements of control l, and electric igniter 9 which enkindles gas emanating from burner 2.

Gas burner 2 is known as a cross-flow type of main burner, and comprises an elongated and rigid tubular casing 11 with a cylindrical passageway 13 formed therein (FIGS. 2 and. 5) Casing 11 is arranged with its longitudinal axis in the horizontal, as shown in FIG. 2. To furnish a means for egress from the burner 22, a flattened projecting rib 15 extends outwardly and upwardly from the generally cylindrical peripheral contour of casing 11. Rib 15 is in parallel disposition to the longitudinal axis of easing ll. Two rows of ports 17 (FIGS. 5 and 6) are formed through rib l5 and the inner wall of casing 11 to communicate with passageway 13. In operation of the burner, when a suitable controlling valve (not shown) is opened, a mixture of combustible gases and primary air is conducted through passageway 13 and ports 17, the mixture then being ignited to provide a burner flame which emanates from the ports 1'7.

To signal the presence or absence of flame in a novel and elficient manner to associated contacts of the safety control 1, as shown in FIGS. 5 and 6, the flame detector 3 has been provided. Flame detector 3' is of very simple construction, basically including an elongated tube 19 mounted in cantilever fashion and arranged to warp or bend in response to heat imparted thereto by the flame, an elongated actuating rod 21 which is carried by and extends outwardly from within the tube 19 to amplify the thermally responsive warpage of the tube, and a threaded actuating screw 23 which is carried by the rod 21 and engages the movable contact support arms 25,26, as shown in FIG. 6, of a pair of normally closed switches to signal the flame condition to the safety control circuit.

For a more detailed explanation of the structure of flame detector 3, attention is first directed to actuating rod 21. The rod 21 is slender in configuration, being extended through supported end 27 of the tube 19, and supported in cantilever fashion from within the tube by welding opposite edges 23a and 23b of rod end 28 to diametrically opposite sides 29a and 29b of the front inner wall of tube 19. (See FIG. 6.) The welded sides 29a and 2912 are near free end 29 of tube 19, as shown in FIGS. 6 and 8.

To support end 27 of tube 19, the U-shaped support 30 has been utilized. Support 30', which is shown in FIG. 8, forms a part of control box 7. In particular, support 30 includes parallel walls 31 and 33, the wall 33 being disposed closest to the burner 2. See FIG. 2.) The supported end 27 of flame detector tube 19 is fastened to an aperture in wall 33 of support 3% by raising an annular shoulder 35 on tube 19 near its end 2.7 and turning outwardly the extreme end 27 of the tube to form a flanged lip 37 (FIG. 6). The tube 19 of the flame detector 3 is thus inserted through the aperture in wall 33, as shown in FIG. 6, and rim 39 of this aperture is sandwiched between shoulder 35 and lip 37 to securely support tube 19 in cantilever fashion from wall 33.

The rod 21 is axially arranged in tube 19 so that the plane in which the rod is generally located is parallel to the top of burner rib 15 (FIG. and in perpendicular relationship with elongated plate 43 of support 39 (FIGS. 7 and 8). The purpose of this arrangement of the rod 21 shall become apparent hereinafter, The free end 41 of actuating rod 21 extends away from burner 2 into control box 5 (FIG. 6). For adjustably supporting and positioning actuating screw 23 on rod 21, an L-shaped member 45 has been provided. L-shaped member 45 is welded to the free end 41 of rod 21. Section 47 of member 45 has a tapped hole (not shown) and a locking nut 48 which are engaged by actuating screw 23, as shown in FIG. 6. The inner end 49 of screw 23 (FIG. 6) is spaced slightly from head 51 of a stud-shaped element 53 when no flame is present at burner 2.

The movable contact support arms 25 and 26 are best shown fragmentarily in FIG. 6. These support arms are arranged in parallel overlying relationship, and supported in cantilever fashion along with other elements of control box 7 within stack 55 (FIG. 8). The shank of insulating element 53 is extended through an aperture formed in the free end of arm 25 and the neck of element 53 is fastened to arm 25 so that the element moves with the arm 25. An end tip of the shank of element 53 is spaced slightly from the adjacent free end of contact support arm 26 when there is no flame present at burner 2. The contact support arms 25 and 26 each carry contact buttons 57 disposed inwardly of their free ends. The contact buttons 57 of arms 25, 26 are normally biased to a contacts closed position in cooperative engagement with mating contact buttons 57 carried by the cantilevered arms 59, 61 (FIG. 6). When the flame detector tube 19 senses a flame at burner 2, as shall become apparent hereinafter, the contact buttons of the two switches are opened to the position where they are shown in FIG. 6, by movement of actuating screw 23.

Turning now to an explanation of the operation of flame detector 3, attention is directed to FIGS. 5 and 6. Tube 19 is mounted near to and above rib 15 of the burner casing 11, with one of its cylindrical sides 63 located in close roximity to a row of ports 17. (See FIG. 6.) The axis of tube 19 is parallel to the axis of burner casing 11 and just to the right of one side of burner rib 15, viewing FIG. 5. It is now supposed that the valve controlling burner 2 is opened, and that the mixture of gas and primary air which flows through ports 17 has been enkindled by the operation of electric igniter 9. Flame F thereupon issues forth in serial or continuous fashion from the ports 17. Since the flame detector tube 19 has been positioned with its side 63 in close proximity to the burner flame, the side 63 is in general heated by direct impingement of flame F thereupon. Side 63 of tube 19 thus is heated generally faster than the other side 65 of the tube. The more rapid heating of side 63 of tube 19 causes side 63 to expand longitudinally much faster than the relatively cooler side 65 of the tube, thereby effecting warpage or curvature of the tube in a direction crosswise of and away from the burner flame F. Thus in viewing FIG. 6, the free end 29 of tube 19 warps and curves slightly to the right to the position where it is shown in full, the axis of the tube moving generally in a plane parallel to the top of burner rib 15. As the free end 29 of flame detector tube 19 warps away from the flame due to the impingement of the flame upon heated side 63 of tube 19, the supporting edge 26a of actuating rod 21 which is closest to the flame and is attached to the heated side 63 also moves away from the wall 33 at a more rapid rate of expansion than edge 28b. The outer end 28 of rod 21 consequently moves in an edgewise fashion in a direction crosswise of and away from the burner flame F. This edgewise movement of rod 21 is generally in the same plane as that of the movement of the tube axis. As the supported end 28 of rod 21 moves transversely with tube 19 away from flame F, the free end 41 of rod 21 moves edgewise to the left, viewing FIG. 6,

to open the two pairs of contacts 57. More particularly,

the movement of supported end 28 of rod 21 is substantially magnified at free end 41 of rod 21. As the free end 4-1 of rod 21 moves to the left, viewing FIG. 6, the inner end 49 of screw 23 engages head 51 of the studshapcd element 53 to move the two pairs of mating contacts 57 from their normally closed to their open positions. This signals the presence of flame F to the safety control circuit.

Since the warping movement of flame detector tube 19 is caused only by a difference in expansion between opposite sides of the tube, its action, and the movement of rod 21 is not affected at all by any additional equal expansion of all the sides of the tube, such as may be caused by any increase in ambient temperature.

Turning now to a very important aspect of my invention, which concerns an improved means for enhancing the efliciency of operation of the flame detector 3, attention is directed to the baflie 5 shown in FIGS. 1-6. Battle 5 is of one-piece rigid metal construction and includes an elongated rectangular side plate section 67 which is attached by two screws 71 to threaded apertures (not shown) formed in a flattened projection 69 of the burner casing 11. (See in particular, FIG. 6.) Projection 69 is formed at end 73 of the burner casing (FIGS. 1 and 6), and the flattened external surface of the projection 69 provides a firm mounting surlace for supporting side section 67 of the baflie 5 and, also, as shall become apparent hereinafter, for supporting control box 7, electric igniter 9 and the flame detector 3.

To further position and support baflie 5 upon and relative to burner 2, as shown in FIG. 6, a positioning flange 75 is turned over from outer end 77 of side plate section 67 in perpendicular fashion. Flange 75 is parallel to wall 33 of support 30 and includes two angularly related edges 79 and 81 which conform to adjacent transverse top and side surfaces of burner rib 15 (FIG. 2) for accurately positioning the outer end of balfle 5 thereupon.

To mount control box 7 and flame detector 3 to the baflle 5 and also thereby support these control components upon burner 2, the end of side plate section 67 closest to wall 33 of support 39 is turned over at 83 to provide a flange 35 (as shown in FlG. 6). Flange 85 is generally perpendicular to side plate section 67 and is securely fastened to wall 33 in parallel relationship therewith by means of the two screws 87 (FIG. 3). It will thus be seen that control box '7 and flame detector 3 are attached to burner 2 and supported thereon via their securement to baffle 5.

Between the flanged ends 75 and 35 of battle 5, a pair of upper and lower rectangular deflecting plates 39 and 91, respectively, are turned over at upper and lower longitudinal creases 90 and 92 from side plate section 67. (See FIGS. 1 and 5.) The plates 39 and 91 are disposed in parallel relationship to each other as well as to flame de tector rod 21 and to the outer flattened surface of burner rib 15. Upper plate 89 is generally disposed horizontally in the same plane as slender rod 21, the free end edge 93 of the plate 39 being separated from the adjacent side of flame detector tube 19 by opening A. The lower plate 91 is generally disposed horizontally in a plane which includes the axis of burner 2, the free end edge 95 of plate 91 being 5 eparated from the adjacent side of burner casing 11 by opening B.

For an understanding of the purpose of the upper and lower deflecting plates 8? and 91, attention is directed to FIG. 5. As shown in FIGURE 5, the principal direction of air movement is upward. This direction is determined by the direction of blower action as well as the direction of iiow of aspirated air due to the burning gases. As the ignited gas and primary air mixture issues forth upwardly from burner ports 17, the flame F propagates either continuously or serially in an elongated fashion along side 63 of the flame detector tube 1%. The flame propagated by the row of ports 17 closest to side 63 of tube 19, impinges upon the side 63 in a direction crosswise to the axis of the tube 19 and generally tangent to its curvature. (See also FIG. 6.)

As previously set forth, flame detector 3 actuates a pair OI" switches by thermal warpage of the tube 19. To enhence the efficiency of operation or" flame detector 3, the deflecting plates 8d and 91 of my invention control the movement t secondary air to the flame detector tube 19. In particular, with the burner mounted in the position shown in P16. 5, secondary air initially flows through opening B in the direction indicated by the enlarged reference arrows. The size of opening B controls the amount of secondary air which moves on an upward course toward tube 19 and flame F. Some of the secondary air which enters upwardly at opening B then flows transversely to the left and around the heated skin of side as of the tube 19 to raise the skin temperature of the portion of flame F impinging upon side as. The rest of the secondary air which has entered the baiiie 5 at opening B flows up and around the relatively cool side 65 of tube 19, and helps to cool that side of the tube by lowering the skin temperature thereof. The size of the opening A controls the amount of secondary air which flows to the sides as and of the flame detector tube from opening B.

By proportioning the sizes of openings A and B for the desired fuel mixture and other various characteristics which effect the flame F, the flame F is restricted to approximately one half of tube 19, which tube half is referred to as side 63. A portion of frame F of relatively high temperature in consonance with the fuel mixture involved is thereby directed to the reactive side 63 of the flame detector. At the same time, the skin temperature of the relatively cool side 65 of the tube is reduced. By raising the skin temperature on side as of tube 11 and concurrently lowering the skin temperature at side 65 of the tube, the time of the reaction of tube which is necessary to actuate the flame detector contacts to their open position is considerably reduced. With such a baffle arrangement, an improved thermally responsive device which is very quickly responsive to the presence or absence of a flame is thus thereby achieved.

For igniting the gas and primary air mixture emanating from burner ports 17, my improved safety control unit 1 includes the aforementioned electric igniter 9. The particular construction and mode or" operation of igniter S comprises the invention of Gaylord H. Wotring, and this construction and arrangement are described and claimed in his copending application Serial No. 125,557 filed concurrently herewith and assigned to the same assignee as the present invention.

To briefly describe this igniter 9, it includes a stationary field structure (not shown) located within and including casing 5 7 (FlG. 3). This stationary field structure also includes a winding which is connected in series with fixed and rotatably movable electrodes 19 and 181, respectively. (See FIG. 2) The fixed and movable electrodes 99 and 191 have cooperating tungsten contacts 1&3 at the free ends thereof. Spring 1135 normally biases the movable electrode 1111 into rotative engagement with fixed electrode 92 When the field winding of the igniter 9 is energized, salient poles of a rotor which is attached to the movable electrode line up with salient poles or" the casing 97 to rotate the free end of the movable electrode through an angle of approximately 60. The series connection of the igniter winding and the electrodes is energized by an alternating current source connected across terminals 1117 (FIG. 3) and 1G9 (FIG. 2). With such an arrangement, when current flows across the terminals It and 109, the normally closed movable electrode 101 is initially driven open by excitation of the rotor. The movable electrode 181 then rotates through an arc of approximately 60", providing an arc voltage drop across the electrodes. Since the winding is in series with the electrode contacts 103, when the contacts open, the Winding is deenergized. Spring 1 35 then acts upon the movable electrode 101 and rotates the movable electrode contact back into engagement with the mating contact of the fixed electrode 99. As long as current iiows across the terminals 107 and 1119 (i.e., through the igniter circuit), movable electrode 1131 will thus rotatably oscillate through an angle of approximately 60, producing an are each time.

For supporting the electric igniter 9 and positioning it in a proper physical relationship to burner 2, bracket 111 and two threaded mounting screws 113 have been provided. (See FIGS. 3 and 4). Bracket 111 has an elongated cylindrical section 115 (FIG. 4) which conforms to a portion of the cylindrical igniter casing '97 and is welded thereto. The bracket 111 also includes a flat flange 117 separated from cylindrical section 115 by an angularly related connecting wall (PEG. 4). Screws 113 are extended through apertures in flange 117 into threaded engagement with aligned apertures (not shown) formed in the elongated support plate 43 (FIGS. 3 and 7). The igniter 9 is thus positioned upon and supported by plate 43 of the control box 7, with the tungsten contacts 1113 disposed above and adjacent to fuel ports 17 of the burner (FIG. 2). In particular, the plane of contiguous engagement of the contacts 103 is parallel to and in spaced proximity to the outer surface of rib 15 of the burner 2, and the contacts 1% at least partially overlie one row of the burner ports 17.

Turning now to a further explanation of the control box 7 of my safety control unit 1, attention is first directed to'FIGS. 14. To compactly house and contain various safety controlling elements of control unit 1, box 7 includes a channel-shaped cover 119. The cover 119 includes a pair of oppositely disposed and elongated walls 121 connected together, as shown in FIG. 4, by intermediate wall 123. To enable cover 119 to compactly cooperate with support 30 to form an over-all housing, walls 121 and 123 each have a flange 125 formed at their ends. The flanges 125, as will be understood from an inspection of FIGS. 2 and 4, extend inwardly and wrap around the side edges 127 (FIGS. 7 and 8) of each of the walls 31 and 33 or" support fall, to mount the cover 119 in complementary cooperation with support 3 The support plate 43 then compactly forms one elongated side or bottom of the housing and the walls 31 and 33 form the ends of the housing. To additionally secure cover 119 to su port 34?, flange 125a, which is at the end of cover 119 most removed from bafile 5 (FIG. 4), has a bifurcated extension 12% which is fastened by screw 131 to a threaded aperture in wall 31 of support 31?.

FIGS. 7 and 8 illustrate the arrangement of the various safety controlling elements in control box 7. On the left side of support 39, near wall 31 thereof, a control or ignition relay 132 is located. Relay 132 includes a coil 133, frame 135, and armature 137. Coil 133 of relay 132 is positioned within the U-shaped frame 135, as shown in FIG. 8. The armature 137 is L-shaped and it is pivotally supported on frame 135 by fitting an indented neck of the armature into an appropriate recess in the frame, as shown in FIG. 7. One end 13? of the relay armature 137 is normally biased away from core 141 of the relay (as shown in FIG. 8) by spring 143 and upon energization of the coil 133 is attracted to the core 141. The spring 143 runs in tension between tab 145 of the armature and a lower tab (not shown) of frame 135. An actuating end 14-7 of armature 137 is thus normally biased by spring 143 to the position wherein it is shown in FIG. 8. In this position, end 147 of the relay armature engages button 149 at the free end of movable contact arm 151 to hold contacts 153 of the ignition relay out of engagement. When coil 133 is energized through terminals 133a and 13315, end 139 of the armature is attracted by core 141 and actuating end 147 of the armature moves upwardly (viewing FIG. 8) to allow the relay contacts 153 to close. It will be understood by those skilled in the art that relay contacts 153 are connected in series circuit relationship with a valve (not shown) that controls the flow of fuel through the burner 2.

On the other side of support 3 there is compactly supported on stack 55 all of the switching elements of control 1. A lockout heater 155 is wrapped around the supporting arm 156 (P16. 7) of one of a normally closed pair of contacts 157. Heater 155 opens contacts 157 when it is energized. The lockout contacts 15? are connected in the safety control circuit to deenerglze the valve and the igniter 9 upon ignition or flame failure.

In viewing FIG. 8, it will be noted that the supporting arm 159 of the relatively fixed relay contact 153 is bent angularly and joined to the second contact supporting arm 16% of one of the lockout contacts 257. The relay contacts 153 and lockout contacts 157 are connected in series relationship by means of the association of these two contact carrying arms 159 and 169.

As shown in FIGS. 7 and 8, the contact supporting arms 25, 59 and 26, 61 of the two switches operated by the flame detector 3 are each generally L shaped, being curved inwardly from stack 55 in the manner illustrated at $5 for arm 59 in FIG. 7. This arrangement allows the supporting arms 25, 59 and 26, 61 to be assembled compactly in overlying relationship alongside of the spaced apart and overlying supporting arms of the relay and lockout contacts.

To facilitate the convenient connection of the elements of safety control unit 1 in circuit with a suitable external controlling switch (such as a thermostat or a timer) and a burner valve, terminal tabs 161 are extended outwardly in parallel and orderly disposition from one side of supporting stack 55. Tabs 161 are fitted through slots formed in a small square of insulating material 163. A slot (not shown) is formed in one of the elongated side walls 121 of cover 119 to facilitate the egress of the terminal tabs 161 from the cover 119.

It will now therefore be seen that my improved safety control unit provides a thermally responsive means which is rapidly and efiiciently operative to detect the presence or absence of a burner flame. It will be further understood that this improved safety control unit is very compact in construction, and readily lends itself to economy of manufacture.

While in accordance with the patent statutes, 1 have described what at present is considered to be the preferred embodiment of my invention, it willbe obvious to those skilled in the art that various changes and modifications may be made therein without departing from my invention, and I therefore aim in the following claims to cover all such equivalent variations as fall within the true spirit and scope of the invention,

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In combination with a horizontal type burner having a plurality of ports for directing jets of flame upwardly therefrom, a control device comprising a flame detector mounted above said ports and in the path of said flame, said detector adapted to operate a switch in response to the impingement of flame directed to one side of said detector, and a bafile means disposed adjacent to both said burner and said flame detector for controlling the impingement of said flame on said one side of said detector and the flow of cooling air around the other side of the flame detector, said baflle means having a first section extending into proximity to said other side of said flame detector and defining a restricted opening therewith for the passage of said cooling air, and a second section extending into proximity to said burner and defining a restricted passage therewith, said second section being positioned below the ports of said burner and controlling the flow of secondary air to said flame and the flow of said cooling air to said restricted opening and the other side of said detector, said detector being disposed in a predetermined position above said burner whereby the secondary air flowing to said flame from said restricted passage causes said flame to be restricted to said one side of said detector while the other side of said detector is cooled by said air.

2. The combination of claim 1 wherein said flame de tector comprises a tubular member disposed in the path of said flame, said tubular member having a continuous outer cylindrical surface, and operating by thermally responsive warpage to actuate said switch.

3. The combination of claim 1 wherein said baflle means comprises a U-shaped section having a side plate and first and second deflecting plates, said side plate joining said first and said second deflecting plates together in spaced apart relationship to one another, and said deflecting plates forming said first and said second sections of said baflle means.

4. The combination of claim 3 wherein said first deflecting plate section extends perpendicularly from the upper edge of said side plate into proximity to said flame detector to define said restricted passageway for said cooling air, and wherein said second deflecting plate section extends perpendicularly from the lower edge of said side plate into proximity to said burner to define said restricted passage therewith.

5. The combination of claim 4 wherein said side plate has an end plate turned over from each end thereof, said two end plates being in parallel relationship and disposed perpendicularly to the planes of said first and said second deflecting plates, means including one of said end plates for supporting said baflle and a safety control housing fastened to the other of said end plates and thereby supported by said baflle.

References Cited in the file of this patent UNITED STATES PATENTS 2,185,436 Gord an Jan. 2, 1940 2,392,065 Rodgers Jan. 1, 1946 2,418,867 Burch Apr. 15, 1947 2,483,939 Schickler Oct. 4, 1949 2,520,399 Higley Aug. 29, 1950 

1. IN COMBINATION WITH A HORIZONTAL TYPE BURNER HAVING A PLURALITY OF PORTS FOR DIRECTING JETS OF FLAME UPWARDLY THEREFROM, A CONTROL DEVICE COMPRISING A FLAME DETECTOR MOUNTED ABOVE SAID PORTS AND IN THE PATH OF SAID FLAME, SAID DETECTOR ADAPTED TO OPERATE A SWITCH IN RESPONSE TO THE IMPINGEMENT OF FLAME DIRECTED TO ONE SIDE OF SAID DETECTOR, AND A BAFFLE MEANS DISPOSED ADJACENT TO BOTH SAID BURNER AND SAID FLAME DETECTOR FOR CONTROLLING THE IMPINGEMENT OF SAID FLAME ON SAID ONE SIDE OF SAID DETECTOR AND THE FLOW OF COOLING AIR AROUND THE OTHER SIDE OF THE FLAME DETECTOR, SAID BAFFLE MEANS HAVING A FIRST SECTION EXTENDING INTO PROXIMITY TO SAID OTHER SIDE OF SAID FLAME DETECTOR AND DEFINING A RESTRICTED OPENING THEREWITH FOR THE PASSAGE OF SAID COOLING AIR, AND A SECOND SECTION EXTENDING INTO PROXIMITY TO SAID BURNER AND DEFINING A RESTRICTED PASSAGE THEREWITH, SAID SECOND SECTION BEING POSITIONED BELOW THE PORTS OF SAID BURNER AND CONTROLLING THE FLOW OF SECONDARY AIR TO SAID FLAME AND THE FLOW OF SAID COOLING AIR TO SAID RESTRICTED OPENING AND THE OTHER SIDE OF SAID DETECTOR, SAID DETECTOR BEING DISPOSED IN A PREDETERMINED POSITION ABOVE SAID BURNER WHEREBY THE SECONDARY AIR FLOWING TO SAID FLAME FROM SAID RESTRICTED PASSAGE CAUSES SAID FLAME TO BE RESTRICTED TO SAID ONE SIDE OF SAID DETECTOR WHILE THE OTHER SIDE OF SAID DETECTOR IS COOLED BY SAID AIR. 